CN112269245A

CN112269245A - Image pickup optical lens

Info

Publication number: CN112269245A
Application number: CN202011461939.XA
Authority: CN
Inventors: 阪口贵之; 崔元善
Original assignee: Changzhou Ruitai Photoelectric Co Ltd
Current assignee: Changzhou Ruitai Photoelectric Co Ltd
Priority date: 2020-12-14
Filing date: 2020-12-14
Publication date: 2021-01-26
Anticipated expiration: 2040-12-14
Also published as: WO2022126696A1; CN112269245B; US20220187573A1

Abstract

The invention relates to the field of optical lenses, and discloses an image pickup optical lens, which comprises six lenses in sequence from an object side to an image side: a first lens element with positive refractive power, a second lens element with negative refractive power, a third lens element with positive refractive power, a fourth lens element with negative refractive power, a fifth lens element with positive refractive power, and a sixth lens element with negative refractive power; the focal length of the imaging optical lens is f, the focal length of the second lens is f2, the central curvature radius of the object-side surface of the third lens is R5, the central curvature radius of the image-side surface of the third lens is R6, the on-axis thickness of the first lens is d1, the on-axis distance from the image-side surface of the first lens to the object-side surface of the second lens is d2, the on-axis thickness of the second lens is d3, and the following relations are satisfied: (d 1+ d 2)/d 3 is not more than 4.00 and not more than 5.50; f2/f is not less than 3.00 and not more than-2.00; R5/R6 is more than or equal to 0.20 and less than or equal to 0.35.

Description

Image pickup optical lens

Technical Field

The present invention relates to the field of optical lenses, and more particularly, to an imaging optical lens suitable for portable terminal devices such as smart phones and digital cameras, and imaging apparatuses such as monitors and PC lenses.

Background

In recent years, with the rise of various smart devices, the demand for miniaturized photographing optical lenses is increasing, and due to the reduction of the pixel size of the photosensitive device and the trend of the electronic products to have a good function and a light, thin and portable appearance, the miniaturized photographing optical lenses with good imaging quality are the mainstream in the market. In order to obtain better imaging quality, a multi-lens structure is often adopted. Moreover, with the development of technology and the increase of diversified demands of users, under the condition that the pixel area of the photosensitive device is continuously reduced and the requirement of the system on the imaging quality is continuously improved, the six-lens structure gradually appears in the design of the lens. There is a strong demand for a wide-angle imaging lens having excellent optical characteristics, a small size, and sufficiently corrected aberrations.

Disclosure of Invention

In view of the above problems, an object of the present invention is to provide an imaging optical lens that has good optical performance and satisfies design requirements for a large aperture, ultra-thin thickness, and wide angle.

To solve the above-mentioned problems, an embodiment of the present invention provides an imaging optical lens, which includes six lenses, in order from an object side to an image side: a first lens element with positive refractive power, a second lens element with negative refractive power, a third lens element with positive refractive power, a fourth lens element with negative refractive power, a fifth lens element with positive refractive power, and a sixth lens element with negative refractive power; the focal length of the imaging optical lens is f, the focal length of the second lens is f2, the central curvature radius of the object-side surface of the third lens is R5, the central curvature radius of the image-side surface of the third lens is R6, the on-axis thickness of the first lens is d1, the on-axis distance from the image-side surface of the first lens to the object-side surface of the second lens is d2, the on-axis thickness of the second lens is d3, and the following relations are satisfied: (d 1+ d 2)/d 3 is not more than 4.00 and not more than 5.50; f2/f is not less than 3.00 and not more than-2.00; R5/R6 is more than or equal to 0.20 and less than or equal to 0.35.

Preferably, the object-side surface of the first lens is convex at the paraxial region; the focal length of the first lens is f1, the central curvature radius of the object side surface of the first lens is R1, the central curvature radius of the image side surface of the first lens is R2, the total optical length of the image pickup optical lens is TTL, and the following relational expression is satisfied: f1/f is more than or equal to 0.39 and less than or equal to 1.64; -3.34 ≤ (R1+ R2)/(R1-R2) ≤ 0.18; d1/TTL is more than or equal to 0.08 and less than or equal to 0.36.

Preferably, the imaging optical lens satisfies the following relational expression: f1/f is more than or equal to 0.62 and less than or equal to 1.31; -2.09 ≤ (R1+ R2)/(R1-R2) is ≤ 0.23; d1/TTL is more than or equal to 0.12 and less than or equal to 0.29.

Preferably, the central radius of curvature of the object-side surface of the second lens element is R3, the central radius of curvature of the image-side surface of the second lens element is R4, and the total optical length of the imaging optical lens system is TTL and satisfies the following relationship: -8.99 ≤ (R3+ R4)/(R3-R4) 3.44; d3/TTL is more than or equal to 0.02 and less than or equal to 0.10.

Preferably, the imaging optical lens satisfies the following relational expression: -5.62 ≦ (R3+ R4)/(R3-R4) 2.75; d3/TTL is more than or equal to 0.03 and less than or equal to 0.08.

Preferably, the object-side surface of the third lens element is convex at the paraxial region, and the image-side surface of the third lens element is concave at the paraxial region; the focal length of the third lens is f3, the on-axis thickness of the third lens is d5, the total optical length of the shooting optical lens is TTL, and the following relational expression is satisfied: f3/f is more than or equal to 1.66 and less than or equal to 11858.63; -4.14 ≤ (R5+ R6)/(R5-R6) ≤ 1.00; d5/TTL is more than or equal to 0.03 and less than or equal to 0.15.

Preferably, the imaging optical lens satisfies the following relational expression: f3/f is more than or equal to 2.66 and less than or equal to 9486.91; -2.59 ≤ (R5+ R6)/(R5-R6) ≤ 1.25; d5/TTL is more than or equal to 0.05 and less than or equal to 0.12.

Preferably, the object-side surface of the fourth lens element is concave at the paraxial region, and the image-side surface of the fourth lens element is convex at the paraxial region; the focal length of the fourth lens is f4, the central curvature radius of the object-side surface of the fourth lens is R7, the central curvature radius of the image-side surface of the fourth lens is R8, the on-axis thickness of the fourth lens is d7, the total optical length of the imaging optical lens is TTL, and the following relations are satisfied: f4/f is not less than 9.00 and not more than-1.19; -16.75 ≤ (R7+ R8)/(R7-R8) ≤ 1.48; d7/TTL is more than or equal to 0.03 and less than or equal to 0.11.

Preferably, the imaging optical lens satisfies the following relational expression: -5.62. ltoreq. f 4/f. ltoreq-1.49; -10.47 ≤ (R7+ R8)/(R7-R8) ≤ 1.86; d7/TTL is more than or equal to 0.04 and less than or equal to 0.08.

Preferably, an object-side surface of the fifth lens element is convex at a paraxial region, and an image-side surface of the fifth lens element is convex at a paraxial region; the focal length of the fifth lens element is f5, the central curvature radius of the object-side surface of the fifth lens element is R9, the central curvature radius of the image-side surface of the fifth lens element is R10, the on-axis thickness of the fifth lens element is d9, the total optical length of the imaging optical lens assembly is TTL, and the following relations are satisfied: f5/f is more than or equal to 0.30 and less than or equal to 1.74; -1.51 ≤ (R9+ R10)/(R9-R10) ≤ 0.14; d9/TTL is more than or equal to 0.05 and less than or equal to 0.17.

Preferably, the imaging optical lens satisfies the following relational expression: f5/f is more than or equal to 0.48 and less than or equal to 1.40; -0.94 ≤ (R9+ R10)/(R9-R10) ≤ 0.18; d9/TTL is more than or equal to 0.08 and less than or equal to 0.14.

Preferably, an object-side surface of the sixth lens element is convex at a paraxial region, and an image-side surface of the sixth lens element is concave at the paraxial region; the focal length of the sixth lens element is f6, the central curvature radius of the object-side surface of the sixth lens element is R11, the central curvature radius of the image-side surface of the sixth lens element is R12, the on-axis thickness of the sixth lens element is d11, the total optical length of the imaging optical lens assembly is TTL, and the following relations are satisfied: f6/f is not less than-2.94 and not more than-0.49; (R11+ R12)/(R11-R12) is not more than 1.25 and not more than 6.49; d11/TTL is more than or equal to 0.03 and less than or equal to 0.12.

Preferably, the imaging optical lens satisfies the following relational expression: f6/f is not less than 1.84 and not more than-0.61; 2.00-5.19 (R11+ R12)/(R11-R12); d11/TTL is more than or equal to 0.05 and less than or equal to 0.10.

Preferably, the image height of the image pickup optical lens is IH, the total optical length of the image pickup optical lens is TTL, and the following relational expression is satisfied: TTL/IH is less than or equal to 1.83.

Preferably, the imaging optical lens satisfies the following relational expression: TTL/IH is less than or equal to 1.80.

Preferably, the field angle FOV of the image pickup optical lens is greater than or equal to 66.19 °.

Preferably, the field angle FOV of the image pickup optical lens is greater than or equal to 67.56 °.

Preferably, the aperture value FNO of the imaging optical lens is less than or equal to 2.90.

Preferably, the aperture value FNO of the imaging optical lens is less than or equal to 2.84.

Preferably, the combined focal length of the first lens and the second lens is f12, and the following relation is satisfied: f12/f is more than or equal to 0.51 and less than or equal to 2.32.

The invention has the beneficial effects that: the imaging optical lens according to the present invention has excellent optical characteristics, and has characteristics of a large aperture, a wide angle of view, and an ultra-thin profile, and is particularly suitable for a mobile phone camera lens module and a WEB camera lens which are constituted by high-pixel imaging elements such as CCDs and CMOSs.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without inventive efforts, wherein:

fig. 1 is a schematic configuration diagram of an imaging optical lens according to a first embodiment of the present invention;

FIG. 2 is a schematic axial aberration diagram of the imaging optical lens of FIG. 1;

fig. 3 is a schematic diagram of chromatic aberration of magnification of the imaging optical lens shown in fig. 1;

FIG. 4 is a schematic view of curvature of field and distortion of the imaging optical lens of FIG. 1;

fig. 5 is a schematic configuration diagram of an imaging optical lens according to a second embodiment of the present invention;

FIG. 6 is a schematic axial aberration diagram of the imaging optical lens of FIG. 5;

fig. 7 is a schematic diagram of chromatic aberration of magnification of the imaging optical lens shown in fig. 5;

FIG. 8 is a schematic view of curvature of field and distortion of the imaging optical lens of FIG. 5;

fig. 9 is a schematic configuration diagram of an imaging optical lens according to a third embodiment of the present invention;

fig. 10 is a schematic view of axial aberrations of the image pickup optical lens shown in fig. 9;

fig. 11 is a schematic diagram of chromatic aberration of magnification of the imaging optical lens shown in fig. 9;

fig. 12 is a schematic view of curvature of field and distortion of the imaging optical lens shown in fig. 9.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, it will be appreciated by those of ordinary skill in the art that numerous technical details are set forth in order to provide a better understanding of the present invention in its various embodiments. However, the technical solution claimed in the present invention can be implemented without these technical details and various changes and modifications based on the following embodiments.

(first embodiment)

Referring to the drawings, the present invention provides an image pickup optical lens 10. Fig. 1 shows an imaging optical lens 10 according to a first embodiment of the present invention, and the imaging optical lens 10 includes six lenses in total. Specifically, the image capturing optical lens system 10, in order from an object side to an image side: the lens comprises a diaphragm S1, a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5 and a sixth lens L6. An optical element such as an optical filter (filter) GF may be disposed between the sixth lens L6 and the image plane Si.

In this embodiment, the first lens L1 is made of plastic, the second lens L2 is made of plastic, the third lens L3 is made of plastic, the fourth lens L4 is made of plastic, the fifth lens L5 is made of plastic, and the sixth lens L6 is made of plastic. In other alternative embodiments, each lens may be made of other materials.

In this embodiment, the on-axis thickness of the first lens L1 is defined as d1, the on-axis distance from the image-side surface of the first lens L1 to the object-side surface of the second lens L2 is defined as d2, and the on-axis thickness of the second lens L2 is defined as d3, so that the following relations are satisfied: the thickness of the front two lenses is reasonably controlled within the range, the processing of the lenses is more facilitated, the product yield is improved, and the cost is reduced.

Defining the focal length f of the image pickup optical lens 10 and the focal length f2 of the second lens L2, the following relations are satisfied: 3.00 ≦ f2/f ≦ -2.00, and it is advantageous to correct aberrations of the optical system by controlling the negative power of the second lens L2 in a reasonable range.

The central curvature radius of the object side surface of the third lens L3 is defined as R5, the central curvature radius of the image side surface of the third lens L3 is defined as R6, and the following relations are satisfied: R5/R6 is more than or equal to 0.20 and less than or equal to 0.35, and the ratio of the central curvature radius of the object side surface of the third lens L3 to the central curvature radius of the image side surface of the third lens L3 is controlled, so that the form of the third lens can be prevented from being excessively bent, the manufacturability of machining and forming of the third lens can be improved, and the aberration of an optical imaging system can be reduced.

In this embodiment, the object-side surface of the first lens element is convex at the paraxial region, and the image-side surface of the first lens element is convex at the paraxial region, and the first lens element L1 has positive refractive power. In other alternative embodiments, the object-side surface and the image-side surface of the first lens L1 may be arranged in other concave and convex distribution.

Defining the focal length f of the image pickup optical lens 10 and the focal length f1 of the first lens L1, the following relations are satisfied: f1/f is 0.39-1.64, and the ratio of the focal length of the first lens L1 to the overall focal length is defined. Within the specified range, the first lens element L1 has a positive refractive power, which is favorable for reducing system aberration and is favorable for the lens to be ultra-thin and wide-angled. Preferably, 0.62. ltoreq. f 1/f. ltoreq.1.31 is satisfied.

The central curvature radius of the object side surface of the first lens L1 is R1, the central curvature radius of the image side surface of the first lens L1 is R2, and the following relational expression is satisfied: 3.34 ≦ (R1+ R2)/(R1-R2) ≦ -0.18, and the shape of the first lens L1 is controlled appropriately so that the first lens L1 can correct the system spherical aberration effectively. Preferably, it satisfies-2.09 ≦ (R1+ R2)/(R1-R2) ≦ -0.23.

The on-axis thickness of the first lens L1 is d1, the total optical length of the imaging optical lens system 10 is TTL, and the following relations are satisfied: d1/TTL is more than or equal to 0.08 and less than or equal to 0.36, and ultra-thinning is facilitated in the conditional expression range. Preferably, 0.12. ltoreq. d 1/TTL. ltoreq.0.29 is satisfied.

In this embodiment, the object-side surface of the second lens element L2 is concave at the paraxial region thereof, and the image-side surface thereof is convex at the paraxial region thereof, and the second lens element L2 has negative refractive power. In other alternative embodiments, the object-side surface and the image-side surface of the first lens L1 may be arranged in other concave and convex distribution.

The central curvature radius of the object side surface of the second lens L2 is defined as R3, the central curvature radius of the image side surface of the second lens L2 is defined as R4, and the following relations are satisfied: the shape of the second lens L2 is regulated to be not less than 8.99 and not more than (R3+ R4)/(R3-R4) and not more than 3.44, and the problem of chromatic aberration on the axis is favorably corrected as the lens is changed to a super-thin wide angle within the range. Preferably, it satisfies-5.62 ≦ (R3+ R4)/(R3-R4). ltoreq.2.75.

The on-axis thickness of the second lens L2 is d3, the total optical length of the imaging optical lens system 10 is TTL, and the following relationship is satisfied: d3/TTL is more than or equal to 0.02 and less than or equal to 0.10, and ultra-thinning is favorably realized within the range of conditional expressions. Preferably, 0.03. ltoreq. d 3/TTL. ltoreq.0.08 is satisfied.

In this embodiment, the object-side surface of the third lens element L3 is convex at the paraxial region thereof, the image-side surface thereof is concave at the paraxial region thereof, and the third lens element L3 has positive refractive power.

Defining the focal length of the image pickup optical lens 10 as f, and the focal length of the third lens L3 as f3, the following relations are satisfied: 1.66 ≦ f3/f ≦ 11858.63, and the system has better imaging quality and lower sensitivity through reasonable distribution of the focal power. Preferably, 2.66. ltoreq. f 3/f. ltoreq. 9486.91 is satisfied.

The central curvature radius of the object side surface of the third lens L3 is R5, the central curvature radius of the image side surface of the third lens L3 is R6, and the following relational expressions are satisfied: 4.14 ≦ (R5+ R6)/(R5-R6) ≦ -1.00, defines the shape of the third lens L3, facilitates the formation of the third lens L3, and can alleviate the deflection degree of the light passing through the lens within the range defined by the conditional expression, thereby effectively reducing the aberration. Preferably, it satisfies-2.59 ≦ (R5+ R6)/(R5-R6) ≦ -1.25.

The on-axis thickness of the third lens L3 is d5, the total optical length of the imaging optical lens system 10 is TTL, and the following relationship is satisfied: d5/TTL is more than or equal to 0.03 and less than or equal to 0.15, and ultra-thinning is favorably realized within the range of conditional expressions. Preferably, 0.05. ltoreq. d 5/TTL. ltoreq.0.12 is satisfied.

In this embodiment, the object-side surface of the fourth lens element L4 is concave at the paraxial region thereof, and the image-side surface thereof is convex at the paraxial region thereof, and the fourth lens element L4 has negative refractive power.

Defining the focal length f of the image pickup optical lens 10 and the focal length f4 of the fourth lens L4, the following relations are satisfied: 9.00 ≦ f4/f ≦ -1.19, allowing better imaging quality and lower sensitivity of the system through reasonable distribution of optical power. Preferably, it satisfies-5.62. ltoreq. f 4/f. ltoreq-1.49.

The central curvature radius of the object side surface of the fourth lens L4 is R7, and the central curvature radius of the image side surface of the fourth lens L4 is R8, and the following relations are satisfied: the shape of the fourth lens L4 is regulated to be not less than 16.75 (R7+ R8)/(R7-R8) and not more than-1.48, and when the shape is within the range, the problem of aberration of an off-axis picture angle is favorably corrected along with the development of ultrathin wide-angle. Preferably, it satisfies-10.47 ≦ (R7+ R8)/(R7-R8). ltoreq.1.86.

The on-axis thickness of the fourth lens L4 is d7, the total optical length of the imaging optical lens system 10 is TTL, and the following relationship is satisfied: d7/TTL is more than or equal to 0.03 and less than or equal to 0.11, and ultra-thinning is favorably realized within the range of conditional expressions. Preferably, 0.04. ltoreq. d 7/TTL. ltoreq.0.08 is satisfied.

In this embodiment, the object-side surface of the fifth lens element L5 is convex at the paraxial region thereof, and the image-side surface thereof is convex at the paraxial region thereof, and the fifth lens element L5 has positive refractive power.

Defining the focal length f of the image pickup optical lens 10 and the focal length f5 of the fifth lens L5, the following relations are satisfied: f5/f is more than or equal to 0.30 and less than or equal to 1.74, and the definition of the fifth lens L5 can effectively make the light ray angle of the shooting optical lens 10 smooth and reduce the tolerance sensitivity. Preferably, 0.48. ltoreq. f 5/f. ltoreq.1.40 is satisfied.

The central curvature radius of the object side surface of the fifth lens L5 is R9, the central curvature radius of the image side surface of the fifth lens L5 is R10, and the following relations are satisfied: -1.51 ≦ (R9+ R10)/(R9-R10) ≦ -0.14, and defines the shape of the fifth lens L5, and is advantageous for correcting the aberration of the off-axis angle and the like with the development of an ultra-thin wide angle in the range. Preferably, it satisfies-0.94 ≦ (R9+ R10)/(R9-R10) ≦ -0.18.

The on-axis thickness of the fifth lens L5 is d9, the total optical length of the imaging optical lens system 10 is TTL, and the following relationship is satisfied: d9/TTL is more than or equal to 0.05 and less than or equal to 0.17, and ultra-thinning is facilitated in the condition formula range. Preferably, 0.08. ltoreq. d 9/TTL. ltoreq.0.14 is satisfied.

In this embodiment, the object-side surface of the sixth lens element L6 is convex at the paraxial region thereof, the image-side surface thereof is concave at the paraxial region thereof, and the sixth lens element L6 has negative refractive power.

Defining the focal length f of the image pickup optical lens 10 and the focal length f6 of the sixth lens L6, the following relations are satisfied: 2.94 ≦ f6/f ≦ -0.49, allowing better imaging quality and lower sensitivity of the system through reasonable distribution of optical power. Preferably, it satisfies-1.84. ltoreq. f 6/f. ltoreq-0.61.

The center curvature radius of the object side surface of the sixth lens L6 is R11, the center curvature radius of the image side surface of the sixth lens L6 is R12, and the following relations are satisfied: 1.25 ≦ (R11+ R12)/(R11-R12) ≦ 6.49, defines the shape of the sixth lens L6, and is advantageous for correcting the aberration of the off-axis picture angle and the like as the ultra-thin wide angle progresses in a condition range. Preferably, 2.00. ltoreq (R11+ R12)/(R11-R12) 5.19 is satisfied.

The on-axis thickness of the sixth lens element L6 is d11, the total optical length of the imaging optical lens system 10 is TTL, and the following relationships are satisfied: d11/TTL is more than or equal to 0.03 and less than or equal to 0.12, and ultra-thinning is favorably realized within the range of conditional expressions. Preferably, 0.05. ltoreq. d 11/TTL. ltoreq.0.10 is satisfied.

In the present embodiment, the image height of the image pickup optical lens 10 is IH, the total optical length of the image pickup optical lens 10 is TTL, and the following relational expression is satisfied: TTL/IH is less than or equal to 1.83, thereby being beneficial to realizing ultra-thinning. Preferably, TTL/IH ≦ 1.80 is satisfied.

In the present embodiment, the field angle FOV of the imaging optical lens 10 is equal to or greater than 66.19 °, thereby achieving a wide angle. Preferably, the field angle FOV of the imaging optical lens 10 is greater than or equal to 67.56 °.

In this embodiment, the aperture value FNO of the imaging optical lens 10 is less than or equal to 2.90, so that a large aperture is realized and the imaging performance of the imaging optical lens is good. Preferably, the aperture value FNO of the imaging optical lens 10 is less than or equal to 2.84.

In the present embodiment, the focal length of the imaging optical lens 10 is defined as f, the combined focal length of the first lens L1 and the second lens L2 is defined as f12, and the following relationship is satisfied: f12/f is not less than 0.51 and not more than 2.32, so that the aberration and distortion of the image pickup optical lens 10 can be eliminated, the back focal length of the image pickup optical lens 10 can be suppressed, and the miniaturization of the image lens system can be maintained. Preferably, 0.81. ltoreq. f 12/f. ltoreq.1.86 is satisfied.

The imaging optical lens 10 has good optical performance and can meet the design requirements of large aperture, wide angle and ultra-thinness; in accordance with the characteristics of the imaging optical lens 10, the imaging optical lens 10 is particularly suitable for a mobile phone imaging lens module and a WEB imaging lens which are configured by an imaging element such as a high-pixel CCD or a CMOS.

The image pickup optical lens 10 of the present invention will be explained below by way of example. The symbols described in the respective examples are as follows. The unit of focal length, on-axis distance, center curvature radius, on-axis thickness, position of the reverse curvature point and the position of the stagnation point is mm.

TTL: the total optical length (on-axis distance from the object side surface of the first lens L1 to the image plane Si) is in mm;

aperture value FNO: is the ratio of the effective focal length and the entrance pupil diameter of the imaging optical lens.

Preferably, the object side surface and/or the image side surface of the lens may be further provided with an inflection point and/or a stagnation point to meet the requirement of high-quality imaging.

Tables 1 and 2 show design data of the imaging optical lens 10 according to the first embodiment of the present invention.

[ TABLE 1 ]

Wherein each symbol has the following meaning.

S1: an aperture;

r: a radius of curvature at the center of the optical surface;

r1: the center radius of curvature of the object side of the first lens L1;

r2: the central radius of curvature of the image-side surface of the first lens L1;

r3: the center radius of curvature of the object side of the second lens L2;

r4: the central radius of curvature of the image-side surface of the second lens L2;

r5: the center radius of curvature of the object side of the third lens L3;

r6: the central radius of curvature of the image-side surface of the third lens L3;

r7: the center radius of curvature of the object side of the fourth lens L4;

r8: the central radius of curvature of the image-side surface of the fourth lens L4;

r9: the center radius of curvature of the object side of the fifth lens L5;

r10: the center radius of curvature of the image-side surface of the fifth lens L5;

r11: the center radius of curvature of the object side of the sixth lens L6;

r12: the center radius of curvature of the image-side surface of the sixth lens L6;

r13: the central radius of curvature of the object side of the optical filter GF;

r14: the center radius of curvature of the image side of the optical filter GF;

d: on-axis thickness of the lenses, on-axis distance between the lenses;

d 0: the on-axis distance of the stop S1 to the object-side surface of the first lens L1;

d 1: the on-axis thickness of the first lens L1;

d 2: the on-axis distance from the image-side surface of the first lens L1 to the object-side surface of the second lens L2;

d 3: the on-axis thickness of the second lens L2;

d 4: the on-axis distance from the image-side surface of the second lens L2 to the object-side surface of the third lens L3;

d 5: the on-axis thickness of the third lens L3;

d 6: the on-axis distance from the image-side surface of the third lens L3 to the object-side surface of the fourth lens L4;

d 7: the on-axis thickness of the fourth lens L4;

d 8: an on-axis distance from an image-side surface of the fourth lens L4 to an object-side surface of the fifth lens L5;

d 9: the on-axis thickness of the fifth lens L5;

d 10: an on-axis distance from an image-side surface of the fifth lens L5 to an object-side surface of the sixth lens L6;

d 11: the on-axis thickness of the sixth lens L6;

d 12: the on-axis distance from the image-side surface of the sixth lens L6 to the object-side surface of the optical filter GF;

d 13: on-axis thickness of the optical filter GF;

d 14: the axial distance from the image side surface of the optical filter GF to the image surface Si;

nd: refractive index of d-line (d-line is green light with wavelength of 550 nm);

nd 1: the refractive index of the d-line of the first lens L1;

nd 2: the refractive index of the d-line of the second lens L2;

nd 3: the refractive index of the d-line of the third lens L3;

nd 4: the refractive index of the d-line of the fourth lens L4;

nd 5: the refractive index of the d-line of the fifth lens L5;

nd 6: the refractive index of the d-line of the sixth lens L6;

ndg: the refractive index of the d-line of the optical filter GF;

vd: an Abbe number;

v 1: abbe number of the first lens L1;

v 2: abbe number of the second lens L2;

v 3: abbe number of the third lens L3;

v 4: abbe number of the fourth lens L4;

v 5: abbe number of the fifth lens L5;

v 6: abbe number of the sixth lens L6;

vg: abbe number of the optical filter GF.

Table 2 shows aspherical surface data of each lens in the imaging optical lens 10 according to the first embodiment of the present invention.

[ TABLE 2 ]

For convenience, an aspherical surface shown in the following formula (1) is used as an aspherical surface of each lens surface. However, the present invention is not limited to the aspherical polynomial form expressed by this formula (1).

。

Where k is a conic coefficient, a4, a6, A8, a10, a12, a14, a16, a18, a20 are aspheric coefficients, c is a curvature at the center of the optical surface, r is a perpendicular distance from a point on an aspheric curve to the optical axis, and z is an aspheric depth (a perpendicular distance between a point on an aspheric surface at a distance of r from the optical axis and a tangent plane tangent to a vertex on the aspheric optical axis).

Tables 3 and 4 show the inflection point and stagnation point design data of each lens in the imaging optical lens 10 according to the first embodiment of the present invention. P1R1 and P1R2 represent the object-side surface and the image-side surface of the first lens L1, P2R1 and P2R2 represent the object-side surface and the image-side surface of the second lens L2, P3R1 and P3R2 represent the object-side surface and the image-side surface of the third lens L3, P4R1 and P4R2 represent the object-side surface and the image-side surface of the fourth lens L4, P5R1 and P5R2 represent the object-side surface and the image-side surface of the fifth lens L5, and P6R1 and P6R2 represent the object-side surface and the image-side surface of the sixth lens L6, respectively. The "inflection point position" field correspondence data is a vertical distance from an inflection point set on each lens surface to the optical axis of the image pickup optical lens 10. The "stagnation point position" field corresponding data is the vertical distance from the stagnation point set on each lens surface to the optical axis of the imaging optical lens 10.

[ TABLE 3 ]

[ TABLE 4 ]

Fig. 2 and 3 are schematic diagrams showing axial aberrations and chromatic aberrations of magnification after light having wavelengths of 486nm, 588nm and 656nm passes through the imaging optical lens 10 according to the first embodiment. Fig. 4 is a schematic view showing curvature of field and distortion of light having a wavelength of 588nm after passing through the imaging optical lens 10 according to the first embodiment, where S is curvature of field in the sagittal direction and T is curvature of field in the tangential direction in fig. 4.

Table 13 shown later shows values corresponding to the parameters specified in the conditional expressions for the respective numerical values in the first, second, and third examples.

As shown in table 13, the first embodiment satisfies each conditional expression.

In the present embodiment, the imaging optical lens 10 has an entrance pupil diameter ENPD of 1.316mm, a full field image height IH of 2.671mm, and a diagonal field angle FOV of 71.28 °, and the imaging optical lens 10 satisfies the design requirements of a large aperture, a wide angle, and a slimness, and has excellent optical characteristics in which on-axis and off-axis chromatic aberration is sufficiently corrected.

(second embodiment)

The second embodiment is basically the same as the first embodiment, the same reference numerals as in the first embodiment, and only different points will be described below.

In a second embodiment, the image-side surface of the first lens element is concave at the paraxial region.

Fig. 5 shows an imaging optical lens 20 according to a second embodiment of the present invention.

Tables 5 and 6 show design data of the imaging optical lens 20 according to the second embodiment of the present invention.

[ TABLE 5 ]

Table 6 shows aspherical surface data of each lens in the imaging optical lens 20 according to the second embodiment of the present invention.

[ TABLE 6 ]

Tables 7 and 8 show the inflection point and stagnation point design data of each lens in the imaging optical lens 20 according to the second embodiment of the present invention.

[ TABLE 7 ]

[ TABLE 8 ]

Fig. 6 and 7 are schematic diagrams showing axial aberrations and chromatic aberrations of magnification of light having wavelengths of 486nm, 588nm and 656nm passing through the imaging optical lens 20 according to the second embodiment. Fig. 8 is a schematic view showing curvature of field and distortion of light having a wavelength of 588nm after passing through the imaging optical lens 20 according to the second embodiment. The field curvature S in fig. 8 is a field curvature in the sagittal direction, and T is a field curvature in the tangential direction.

As shown in table 13, the second embodiment satisfies each conditional expression.

In the present embodiment, the imaging optical lens 20 has an entrance pupil diameter ENPD of 1.391mm, a full field image height IH of 2.671mm, and a diagonal field angle FOV of 68.24 °, and the imaging optical lens 20 satisfies the design requirements of a large aperture, a wide angle, and a slim size, and has excellent optical characteristics with on-axis and off-axis chromatic aberration sufficiently corrected.

(third embodiment)

The third embodiment is basically the same as the first embodiment, the same reference numerals as in the first embodiment, and only different points will be described below.

Fig. 9 shows an imaging optical lens 30 according to a third embodiment of the present invention.

Tables 9 and 10 show design data of the imaging optical lens 30 according to the third embodiment of the present invention.

[ TABLE 9 ]

Table 10 shows aspherical surface data of each lens in the imaging optical lens 30 according to the third embodiment of the present invention.

[ TABLE 10 ]

Tables 11 and 12 show the inflection points and the stagnation point design data of each lens in the imaging optical lens 30 according to the third embodiment of the present invention.

[ TABLE 11 ]

[ TABLE 12 ]

Fig. 10 and 11 are schematic diagrams showing axial aberrations and chromatic aberrations of magnification after light having wavelengths of 486nm, 588nm, and 656nm passes through the imaging optical lens 30 according to the third embodiment. Fig. 12 is a schematic view showing curvature of field and distortion of light having a wavelength of 588nm after passing through the imaging optical lens 30 according to the third embodiment. The field curvature S in fig. 12 is a field curvature in the sagittal direction, and T is a field curvature in the tangential direction.

Table 13 below shows the numerical values corresponding to the respective conditional expressions in the present embodiment, in accordance with the conditional expressions described above. Obviously, the imaging optical lens 30 of the present embodiment satisfies the above conditional expressions.

In the present embodiment, the imaging optical lens 30 has an entrance pupil diameter ENPD of 1.158mm, a full field image height IH of 2.671mm, and a diagonal field angle FOV of 78.40 °, and the imaging optical lens 30 satisfies the design requirements of a large aperture, a wide angle, and a slimness, and has excellent optical characteristics in which on-axis and off-axis chromatic aberration is sufficiently corrected.

[ TABLE 13 ]

It will be understood by those of ordinary skill in the art that the foregoing embodiments are specific embodiments for practicing the invention, and that various changes in form and details may be made therein without departing from the spirit and scope of the invention in practice.

Claims

1. An imaging optical lens, comprising six lens elements in order from an object side to an image side: a first lens element with positive refractive power, a second lens element with negative refractive power, a third lens element with positive refractive power, a fourth lens element with negative refractive power, a fifth lens element with positive refractive power, and a sixth lens element with negative refractive power;

the focal length of the imaging optical lens is f, the focal length of the second lens is f2, the central curvature radius of the object-side surface of the third lens is R5, the central curvature radius of the image-side surface of the third lens is R6, the on-axis thickness of the first lens is d1, the on-axis distance from the image-side surface of the first lens to the object-side surface of the second lens is d2, the on-axis thickness of the second lens is d3, and the following relations are satisfied:

4.00≤（d1+d2）/d3≤5.50；

-3.00≤f2/f≤-2.00；

0.20≤R5/R6≤0.35。

2. the imaging optical lens of claim 1, wherein the object side surface of the first lens is convex at the paraxial region;

the focal length of the first lens is f1, the central curvature radius of the object side surface of the first lens is R1, the central curvature radius of the image side surface of the first lens is R2, the total optical length of the image pickup optical lens is TTL, and the following relational expression is satisfied:

0.39≤f1/f≤1.64；

-3.34≤(R1+R2)/(R1-R2)≤-0.18；

0.08≤d1/TTL≤0.36。

3. the imaging optical lens according to claim 2, wherein the imaging optical lens satisfies the following relationship:

0.62≤f1/f≤1.31；

-2.09≤(R1+R2)/(R1-R2)≤-0.23；

0.12≤d1/TTL≤0.29。

4. the imaging optical lens of claim 1, wherein a central radius of curvature of an object-side surface of the second lens is R3, a central radius of curvature of an image-side surface of the second lens is R4, and an optical total length of the imaging optical lens is TTL and satisfies the following relationship:

-8.99≤(R3+R4)/(R3-R4)≤3.44；

0.02≤d3/TTL≤0.10。

5. the imaging optical lens according to claim 4, wherein the imaging optical lens satisfies the following relation:

-5.62≤(R3+R4)/(R3-R4)≤2.75；

0.03≤d3/TTL≤0.08。

6. the imaging optical lens of claim 1, wherein the object-side surface of the third lens element is convex at paraxial region and the image-side surface of the third lens element is concave at paraxial region;

the focal length of the third lens is f3, the on-axis thickness of the third lens is d5, the total optical length of the shooting optical lens is TTL, and the following relational expression is satisfied:

1.66≤f3/f≤11858.63；

-4.14≤(R5+R6)/(R5-R6)≤-1.00；

0.03≤d5/TTL≤0.15。

7. the imaging optical lens according to claim 6, wherein the imaging optical lens satisfies the following relation:

2.66≤f3/f≤9486.91；

-2.59≤(R5+R6)/(R5-R6)≤-1.25；

0.05≤d5/TTL≤0.12。

8. the imaging optical lens of claim 1, wherein the object-side surface of the fourth lens element is concave at the paraxial region and the image-side surface of the fourth lens element is convex at the paraxial region;

the focal length of the fourth lens is f4, the central curvature radius of the object-side surface of the fourth lens is R7, the central curvature radius of the image-side surface of the fourth lens is R8, the on-axis thickness of the fourth lens is d7, the total optical length of the imaging optical lens is TTL, and the following relations are satisfied:

-9.00≤f4/f≤-1.19；

-16.75≤(R7+R8)/(R7-R8)≤-1.48；

0.03≤d7/TTL≤0.11。

9. the image-pickup optical lens according to claim 8, wherein the image-pickup optical lens satisfies the following relation:

-5.62≤f4/f≤-1.49；

-10.47≤(R7+R8)/(R7-R8)≤-1.86；

0.04≤d7/TTL≤0.08。

10. the imaging optical lens of claim 1, wherein the object-side surface of the fifth lens element is convex at paraxial region and the image-side surface of the fifth lens element is convex at paraxial region;

the focal length of the fifth lens element is f5, the central curvature radius of the object-side surface of the fifth lens element is R9, the central curvature radius of the image-side surface of the fifth lens element is R10, the on-axis thickness of the fifth lens element is d9, the total optical length of the imaging optical lens assembly is TTL, and the following relations are satisfied:

0.30≤f5/f≤1.74；

-1.51≤(R9+R10)/(R9-R10)≤-0.14；

0.05≤d9/TTL≤0.17。

11. the image-pickup optical lens according to claim 10, wherein the image-pickup optical lens satisfies the following relation:

0.48≤f5/f≤1.40；

-0.94≤(R9+R10)/(R9-R10)≤-0.18；

0.08≤d9/TTL≤0.14。

12. the imaging optical lens of claim 1, wherein the object-side surface of the sixth lens element is convex at paraxial region and the image-side surface of the sixth lens element is concave at paraxial region;

the focal length of the sixth lens element is f6, the central curvature radius of the object-side surface of the sixth lens element is R11, the central curvature radius of the image-side surface of the sixth lens element is R12, the on-axis thickness of the sixth lens element is d11, the total optical length of the imaging optical lens assembly is TTL, and the following relations are satisfied:

-2.94≤f6/f≤-0.49；

1.25≤(R11+R12)/(R11-R12)≤6.49；

0.03≤d11/TTL≤0.12。

13. the image-pickup optical lens according to claim 12, wherein the image-pickup optical lens satisfies the following relation:

-1.84≤f6/f≤-0.61；

2.00≤(R11+R12)/(R11-R12)≤5.19；

0.05≤d11/TTL≤0.10。

14. a camera optical lens according to claim 1, wherein the image height of the camera optical lens is IH, the total optical length of the camera optical lens is TTL, and the following relationship is satisfied: TTL/IH is less than or equal to 1.83.

15. The image-pickup optical lens according to claim 14, wherein the image-pickup optical lens satisfies the following relation: TTL/IH is less than or equal to 1.80.

16. The image-pickup optical lens according to claim 1, wherein a field angle FOV of the image-pickup optical lens is greater than or equal to 66.19 °.

17. The image-capturing optical lens of claim 16, wherein a field angle FOV of the image-capturing optical lens is greater than or equal to 67.56 °.

18. The imaging optical lens according to claim 1, wherein an aperture value FNO of the imaging optical lens is less than or equal to 2.90.

19. The image-taking optical lens according to claim 18, wherein an aperture value FNO of the image-taking optical lens is less than or equal to 2.84.

20. The imaging optical lens according to claim 1, wherein a combined focal length of the first lens and the second lens is f12, and the following relationship is satisfied: f12/f is more than or equal to 0.51 and less than or equal to 2.32.